Revealing mistake: When Dracula flies into the room to stop his brides from devouring Jonathan, the board carrying him is visible. (00:34:10)
Revealing mistake: When the kids are burying Gus, his supposedly dead face flinches when they shovel dirt on him.
Revealing mistake: After Mary Robert jumps out of the car, you can see the stunt double falling for her.
Revealing mistake: When the terrorists drop the dead body out the aircraft door, look closely at the aeroplane just beneath the door, you can see the reflection of the mat the stuntman lands on, as well as the spotters around it.
Revealing mistake: In the part it shows Ash getting sucked into the time portal you can see the wire he is hanging from. (00:02:45)
Revealing mistake: There is an obvious stunt double for Grandpa during the fight scenes.
Revealing mistake: When Tim Curry runs out of Kevin's hotel room after being scared by the inflatable clown doll he hits his knee on a table. When he hits the table and then hops away you can clearly see that he is wearing a knee-pad.
Revealing mistake: During the ghost of Christmas present, Kermit is walking with tiny Tim on his shoulder and you can tell Kermit is walking on a spinning drum. Right before the camera pans away you can see Kermit's feet slide like he stopped walking but the road kept spinning. (00:55:00)
Revealing mistake: In one scene, the Penguin is making a "bat" shadow puppet on the ceiling. But there's no light behind his hands. If there's no light, there's no shadow. (01:03:45)
Revealing mistake: This is toward the end of the movie. The scene where Dr. Giggles has a waiting room full of his victims. If you watch closely, you will see the blonde corpse blink her eyes.
Revealing mistake: In the jail scene, Gene Hackman is reading from a book. When he turns the book too far towards the camera you catch a glimpse of his lines on brighter white paper attached inside the book.
Revealing mistake: When George Newton comes into the house and it is raining he has an umbrella in his hand. If you look outside his door underneath the balcony it's wet, but further down the path the ground is dry.
Revealing mistake: Towards the end of the movie where Veronica Roberts hands are tied behind her back, she goes over to the mulching machine to cut the rope free. But as she hits the blades they bend and move like rubber.
Revealing mistake: In the scene where Sarah (David's sister) punches one of the Delaney brothers after being harrassed in the alley, she draws back to throw a punch. She first bangs her hand on the brick wall then, after she throws the punch, she punches the other brick wall extremely hard. You can see her bend over whencing in pain and grabbing her hand right before they switch camera views. When they switch camera angles, she's no longer crouched over and she's obviously had time to recover. (01:37:15)
Revealing mistake: When Ryback jury-rigs a timed explosive to destroy the helicopter, he uses a tin of paint thinner which is expected to fall off a hand grenade, thus releasing the spring on the grenade. However, when the explosion occurs you can see over Ryback's shoulder that the paint thinner tin hasn't moved at all, and that the explosion occurs inside the helicopter, not where the grenade was placed.
Revealing mistake: When Pinhead is killing the patrons at the club and they are running away to try and escape, you can see some of them laughing instead of screaming like they should be.
Revealing mistake: After they leave the fort, in the forest glade when the Huron start hollering, the air above the soldiers is very clear. But in the next shot just when the guns start to fire, there is a smoky haze hanging over the forest. Apparently the first attempt to film this scene didn't make it to film and some of the residual smoke was still there when they filmed it the second time.
Revealing mistake: While Nick and his father are driving home with the giant baby behind (an obvious green screen projection), the baby breaks a tube from the car and throws it to the floor. Nick bends down to pick up a prop located offscreen, to add up for realism, but the problem is that he bends down before the baby throws it, so the whole trick is revealed.
Revealing mistake: The film is supposed to be in Alabama, but it was actually shot in Georgia. You can see this when Vinny and Mona are first pulling into the town and they are turning left, in the shot you can see the Georgia State Highway road signs off in the distance. (00:13:20)
Revealing mistake: Near the beginning when they are in the pool and the first earthquake hits. You can see a board covered in soil lift up, which the dog is on.